This puzzle:

Finn Vigeland notes: I dreamed this foul-weather puzzle up on a beautiful sunny day. The goal was to think of 21-letter phrases that hadn't before appeared in the Times, and the revealer at 66-Across came to mind pretty quickly. While it was always the idea to have the theme answers go down (and with circles representing raindrops), for some reason, it never crossed my mind to make that revealer go vertically down as well — I was always beholden to the idea that the theme answers should intersect 66-Across.

So, contrary to what Rex Parker wrote in his review, it actually proved very difficult to find theme entries containing cats and dogs, of equal length, and which intersected the central answer at the right moment. As it often is, the weakest of the theme answers (CABLE SITCOMS ... it's not really a real phrase, though I think my clue redeems it) was the first one I came up with, and my favorite themer (BREAKING THE RULES) was the last one in place. Rejected entries include TRAIN ROBBERY (tabby), PROOF OF DELIVERY (poodle), and OBTUSE TRIANGLE (beagle). At one point in time, I also had ANIMAL CRACKER going down the center of the puzzle, clued as something like [Kid's snack ... or what you are when you solve this puzzle?] before I realized that was just a liiiittle too over the top.